The pelvic girdle serves as the crucial connection between the legs and the core of the body, consisting solely of the right and left coxal bones, also known as os coxae. These bones, along with the sacrum, form the pelvis, which encircles the pelvic cavity and facilitates the transfer of body weight from the vertebral column to the hips and legs.

The coxal bone is formed by the fusion of three distinct bones: the ilium, ischium, and pubis. The ilium, the superior and flattish region of the coxal bone, features the iliac crest, which can be felt at the hips and serves as an attachment point for muscles. A mnemonic to remember the ilium is its similarity in sound to "I like," suggesting a connection to the hips.

Moving down, the ischium forms the lower posterior region of the coxal bone, often referred to as the "sit bones" due to their location. The round shape of the ischium can be associated with the rounded nature of the rear end. The obturator foramen, a noticeable hole in the coxal bone, is situated between the ischium and the pubis, allowing for the passage of nerves and blood vessels.

The pubis, or pubic bone, occupies the lower anterior region of the coxal bone, located just above the genital area. The two coxal bones meet at the pubic symphysis, a cartilaginous joint that allows for slight movement, particularly during pregnancy when hormonal changes can increase flexibility.

At the center of the coxal bone is the acetabulum, the hip socket formed by the convergence of the ilium, ischium, and pubis. This deep socket accommodates the head of the femur, allowing for articulation. The orientation of the coxal bone can be determined by positioning the iliac crest at the top, the pointy pubis at the front, and the acetabulum facing outward, indicating the right coxal bone.

In contrast to the highly mobile pectoral girdle, the pelvic girdle is designed for stability and weight transfer, with limited movement at the acetabulum and the joints formed with the sacrum and pubic symphysis. This structural rigidity is essential for supporting the body's weight during various activities.

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